html , body { width: 100% }
body,
h1,h2,h3,h4,h5,h6,
p,
ul,ol,
div,
header,
section,
footer,
form,
table {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
a {
    text-decoration: none;
    color: #000;
    /* 移除链接标签在移动端点击高亮效果 */
    -webkit-tap-highlight-color:  transparent;
}
input, button {
    border: 0;
}
input{
    outline: none;
}
ul , ol {
    list-style: none;
}

.fl {
    float: left;
}
.fr {
    float: right;
}
.clearfix::after {
    content: "";
    display: block;
    clear: both;
}

html {
    /* 1rem = 37.5px */
    font-size: 37.5px;
}
body {
    font-size: 16px;
}
a, button {
    cursor: pointer;
}